1. Field of the Invention
The present invention relates to heating devices, and more particularly pertains to a new and improved gas fired forced air heating device. Wood burning stoves and fireplaces create a relatively large amount of air pollution as compared with efficient clean burning gas heating devices. Many areas now recognize the acute pollution problems created by a large number of wood burning heating devices. For example, Denver, Colo. has voluntary non-burn days and is currently considering a law limiting the burning of wood on high pollution days. Aspen, Colo. currently has a ban on the construction of new fireplaces. In addition to the pollution problems created by such wood burning heating devices, these devices necessitate the collecting, cutting, splitting, drying and storing of firewood. Alternatively, firewood may be purchased at increasingly high prices. In order to overcome these problems, the present invention provides an efficient gas burning heating device which may be utilized as an insert in a conventional fireplace or which alternatively may be constructed as a free standing unit.
2. Description of the Prior Art
Various types of heating devices are known in the prior art. A typical example of such a heating device is to be found in U.S. Pat. No. 3,601,115, which issued to R. Weatherston on Aug. 24, 1971. This patent discloses a high-flame facing area heat exchanger in which the air passage ways pass both around and through the combustion chamber in a repetitive crisscross pattern. U.S. Pat. No. 3,712,286, which issued to C. Nelson on Jan. 23, 1973, discloses a heat exchanger having an elongated combustion chamber with a burner opening in one end and a pair of ducts leading from the other end to a pair of separate headers. Two groups of tubes extend from the two headers along the combustion chamber for connection with a common header and a third group of tubes extend from the common header to a combustion gas discharge header positioned between the first two headers. U.S. Pat. No. 4,478,206, which issued to H. Ahn on Oct. 23, 1984, discloses a secondary heat exchanger installed above the preliminary heat exchanger in a down draft type gas burning furnace. U.S. Pat. No. 4,558,689, which issued to A. McCann on Dec. 17, 1985, discloses a secondary heat exchanger positioned within a cold air return plenum of a forced air gas or oil fired furnace to preheat cold air drawn into the furnace through the cold air plenum. U.S. Pat. 4,579,102, which issued to E. Sukup on Apr. 1, 1986, discloses a hot air heat exchanger furnace that uses crop residue as a fuel source and is utilized for producing the heat required for drying of grains and other crop products. The furnace includes a combustion chamber, an upper manifold, a lower manifold, a plenum and a number of exhaust tubes.
While the above mentioned devices are suited for their intended usage, none of these devices provide a gas fired forced air heating unit suitable for use as an insert in a conventional fireplace. Additionally, none of the aforesaid devices disclose a heating unit which utilizes a plurality of room air outlet conduits each in fluid communication with a hollow enclosed heat exchanger having an elongated corrugated heat conducting interior metal plate and provided with a bottom heat conductive metal plate disposed adjacent a gas burner. Inasmuch as the art is relatively crowded with respect to these various types of heating devices, it can be appreciated that there is a continuing need for and interest in improvements to such heating devices, and in this respect, the present invention addresses this need and interest.